The invention relates to a running surface for a winter sports apparatus, more precisely to the enhancement of the gliding properties of such a running surface.
Currently used running surfaces for winter sports apparatus, e.g. any types of skis (e.g. cross-country skis, alpine skis, telemark skis), snowboards, skiboards, sleds etc., in more general terms for any running surface intended for gliding on snow or ice are preferably made of hydrophobic plastics, e.g. polyethylene (PE). The mechanism of gliding of such running surfaces on snow and/or ice is yet not fully understood. However, it is believed that upon interaction of surface roughness and snow- or ice crystals a hydrodynamic lubricating effect upon melt water due to frictional heat is essentially involved.
At higher gliding speed, the locally formed melt water tends to spread all over the running surface, leading to an unwanted “suction effect” which may influence the gliding speed in a negative way. In order to overcome this phenomenon, additives such as soot, carbon black and graphite have been added to the polyethylene matrix (see e.g. CH 657 993 A and CH 660 018 A). These additives are supposed to diminish the “suction effect” due to their higher heat conductivity. The superior gliding properties of such modified running surfaces led to their preferential use today. However, these running surfaces are inevitably black due to the black color of soot, carbon black and graphite, thus hampering any alternative coloration of running surfaces. Moreover, there is a high need for further improved gliding properties of running surfaces, especially for sports competition purposes.